Apparatus for forming combination curved and straight glass



y 1944- E. R. BoYLES ET AL 3 82 APPARATUS FOR FORMING COMBINATION CURVED AND STRAIGHT GLASS Filed Dec. 26, 1940 INVENTORS. C'm/mvcs M /D/777/.50/YI BY fDGflR R. 301 456 Patented May 9, 1944 A the simultaneous bending of a plurality of sheets therebetween, thereby forming a composite mp ure, it sags by i s wn W h nd takes same facility as heavier sheets of glass. healed- Y The present invention also lends itself to the It will be appr iated that insofar as the presexpeditious and continuous production ofbent ent apparatus s n e ned. when the molds are gla 30 of concave character with reference to the glass UNITED STATES PATENT OFFICE APPARATUS FOR FORMING COMBINATION CURVED AND STRAIGHT GLASS Edgar R. Boyles and Clarence M. Pattlson, Harti'ord City, Ind., assignors to The Johnston Glass 00., Inc., Hartford City, hill, a corporation Application December 26, 1940, Serial No. 371,702 Claims. (Cl. 49-67) This invention relates to apparatus for bend- In utilizing the apparatus, the several molds ing sheet glass fora variety of uses. after being properly cleaned and coated, have The apparatus herein, however, may be utithe glass applied thereto and glass and mold are lized for the bending of single sheets of glass or approximately at room temperature, although from previous use the mold may be somewhat of glass when curved laminated glass structures warmer, although this diflerence is insumcient are to be fabricated, to have any material effect on the glass or ii No claim is made herein to methods of fabrithe coating on the mold be of combustible charcating safety glass but it is pointed out that the acter to cause or initiate combustion of that present apparatus produces a plurality of glass in layers suitable for safety glass formation of. The glass and mold then are grad y curved or bent character which have confront- .iected to increasing temperatures. e r e of ing surfaces that are substantially complemenheating is suitably controlled so that the mold tary throughout their entire area regardless of and glass are grad y b ou t up to a curvature or curvatures wherebya uniform l5 Perature known s h fte ing temp re o thi k of plastic at may t l that glass. When the glass has reached this safety glass sheet of bent or curved character the shape of t e metal mold and immedi tely which is of uniform thickness throughout and after assuming that p the o d and bent hence, is not subject to variation in strains and 8188s are Subjected to pr e vely 0 1er temstresses incident to variation, lack of contact Deratures unth the mold nd l ss are 0001 between surfaces, et cetera, well known in the enough to n le With ut the use of tools. la i at d r safety glass indu tr The cooling period, of necessity, is of such Th present v ti t l t th duration that the glass in cooling will not have formation of bent sheet glass which is capable of 5 set D therein Strains e l no n n h industryutilization with thin sheets of glass with the In other Words, the glass w n 0 1 has been an- The molds utilized in the present invention supporting a e. the temperatures above and are of such a character that they heat up apvheleW h mold and glass c b pproximately proximately at the same rate as the glass and the same- Whe however. he ld s pportin they cool ofl at substantially the same rate and surface is of convex character. it has n fo n one suitable form of mold is a sheet metal mold. the temperature the mold and glass should It' also has been found that the smoother the be higher than, the er ture below the mold surface of the mold the better thefinish and and glass o facilitate xpeditious conformance ware obtained therefro The mold surface of the glass to h m ldmay be coated with any one of several well In Order to retain the high polish in sheet known mat rial 7 40 glass, known as window glass, and in order to In certain instances where temperature con- Prevent burning 0f the surface, it important 1 can be very closely regulated a the molds that the temperature control be such that the can be mechanically cleaned and have a high glass and mold immediately start to cool after polished surface ware has been suc es full the glass has been softened and has conformed duced, having the desired finish, without the use to the moldof any coating material whatsoever applied to Furthermore. it is e a ly pp rent that when t l surface thicker sheets than those first described, are

The molds preferably are of thin sheet metal being bent, higher temperatures m y pos ibly tempered to withstand heating to a temperature a be necessarysuilicient' to soften sheet glass. Temperatures '50 All Of the aforesaid applies to h n ing 0r sufiicient to soften sheet glass vary from about curving of a single sheet of glass or a pl r i 1,000 F. to 1,500 E, the operating range being of sheets of glass and the annealing thereof. In approximately between 1,050 F. and 1,400 F. the bending or curving of a plurality of sheets The thickness or the sheet and the kind of glass of glass. the l wing pr cautions are to be obdetermines the softening point of that glass. as servedr The mid maybe coated. as ef re. and

here to each other. 1 Thenthe .of glass which are p'erfectly'clean, are placed :on

the mold and subjected to heat -in-theamanner I glass r-sheet' and .a heat shield. .usuitably secured to .;-the: underface r.- theleglass .'sheet i l i lt n .-.member ;ris, azu 'thef numeralqllt 'ndshavingithe-slowerginwardly I r is to be understood thatii thesmoldsiaregshaped the several sheets of said sheets contain no anything else which wouldthat sheet or perhaps causeglass are cleanedsoithat 'dirtor flne .particlesor the sheets to 1 adindicated, and subject: to'the .controls and- 'cau tions previously described. a While allo'f the-.aforesaiddescri-ption has been; 1 directed to. the bending. offglasst-in;aseoncaveand convex conformation, ilimlted toonef'directiom it include variations thereof;

the complementary. mold conformation.

One characteristic of the present invention is Y that the mold is of openwork, that-is, of skeleton lik'e character and by reason .ofthe: resultingopenworl: arrangement whereby. the glass is exposed except shielding means are provided, all as hereinafter more specifically pointed out in detail. a p

The foregoing apparatus is expeditious because when the glass mass is heated and the heat is properly controlled, a maximum of perfect ware is p a minimum cost of production.

produced and at By way of illustration, apparatus suitable for practicing the process now will be described. In the drawing in this application, Fig. 1 is a perspective view of the mold structure apparatus embodied in the invention, the glass sheet being mounted thereon and shown in the bent formation substantially as it would appear when discharged or taken from the lehr.

Fig. 2 is a longitudinal sectional view of the same, the dotted lines therein illustrating the position of the flat glass sheet previous to bending.

It has been ascertained that in the bending of a sheet of flat glass or the simultaneous bending of a plurality of sheets of flat glass wherein only a portion of the glass is to be bent and the remainder is to' retain its original flatness, that the flat glass portion, or portions, usually is in contact with the mold surface long enough to cause objectionable pitting or burning. Such defects especially are objectionable in instances where the glass is intended for use in aeroplanes, lenses and the like.

The apparatus shown in Figs. 1 and 2 herein includes an angle plate In having a downwardly marthesurface-of two or more sheets convex-or concave in.two.:-transversedirectionsor t e il in glass sheetor sheets wheniconfromedthereto-will" have posite end :-'be ars ionathe -'portion: Il .jofi'tljl'e'? glass k supporting surface. tioned, aheatshieldis'applied'i :Hereiiithe same where mold contacted certainheat,

and inwardly directed ledge portion Illa and to the upper surface of which is suitably secured a plurality of spaced bars or beams II. Herein three are shown-two near the ends of the angle plate 10 and one approximately midway thereof. The opposite ends of the angle parts have suitably secured thereto as by spot-welding, or the like, as at Ila, another angle plate l2 having a downwardly and inwardly directed portion Ila.

The sheet metal glass supporting and forming surface template includes the portion l3 suitably secured to the upper surface of the upper ends of the bars II and the other end H of said template is suitably secured-to the downwardly and inwardly directed flange lZa, as shown. Herein the intermediate portion of said template is indicated by the numeral Hi. There is provided an aperture IS in the portion vided an aperture "in the portion l5. These two apertures preferably are continuations of each other and each constitutes an open-work supporting surface metal member, it

IS and there is pro-- will be :,rectedportion?22 W .,ported;iby--jthe bars glll -"A:-'indieates'thegflat glass sheet which .isplacedi -on thei moldstructurez'with pone. ari'dg thet'lower .end'poearinggon- Ethef top-.1 9.

' However, a

mation -|l.

ormay not be ly between LI'AdJacen't the;baranchored sea er the supportshaped .memben desi nate uby Fan'dathe upperginwardlwdi- Thes' Z Theuppenrendfiofgthezeiglass-islieetiand the"op- After 'this has -"been posiis shown as =consistingz of asbestos millboard.

glass ';sh'eet;=A' --adserve as well. --It rests onathe iacent the stop-l9 'and'by reason of theinclinal tion of the shield,'it-bears againstthestop I! as well and is. limited 'in r'movement thereby. The

opposite end is supported bythe inwardly directed portions 22: of the upstanding side members 2 and the sheet merely'restson the inwardly directed portions of said-upright members. These are not continuedacross and joined, since it facilitates flat glass sheet application and curved sheet removal following formation, if the heat shield 23 be removed preliminary to flat sheet application to the mold or curved sheet removal therefrom. V l

Extending across and suitably secured to the several bars H is an angle member 2. The upper'edges thereof terminate in spaced relation to the metal'sheet l3 and as shown in the. figures, another heat shield 25 maybe inserted between the flat sheet l3 and the bars in the construction of the mold and wedgingly secured therein, the wedging action being obtained near .the upper end of the bars II, as shown in -Fig..2t -This shield 25, therefore,

or openwork formation 18 and partially shields but not entirely, the apertureor' openworlrforemployed, depending tions, a heat shield. ofthe same general material may bepositioned uponsthebars l-l near the lower ends'thereoi and "block rising'heat currents. p

With these two heat elds,-it will be obvious that rising heat engaging the underface of the mold structure will-pass upwardly a long the underside of the shield 26 andthence pass inwardthe two shields to engage the lower face of the curved portion l5 of the glass curved supporting portion. The glass sheet following formation is indicated by the letters 13 and C, B

indicating the-flat portion and C vthec'urved portion. D indicates the "free edge of the glass sheet remote from the flat portion-A.

Whenever desired, thereis prcvidedaplurality of angular upright members 30 suitably secured as, at 3| to the portion l2, and the inwardly directed portions 32 extend inwardly and above the angular portion l2a of the member 12 and the portion ll of the glass supporting surface. A strip of heat shielding material and of the character previously described, may be suitably suspended and secured to the inwardly directed r 2 graduallyz diverges from uie -'ba rs -l.l' .-and is supportedaat one or more points jbythereenforcemen 1 metal;'shield-'-or= :other'="shield may shields the" fglass which would normally be exposed through the'bpening' Also, if desired; andgthe-csame-. may' upon c0ndi-- portions 32 as by the bolt and nut means 3 and 34.

It will be readily apparent that the strip or supplementary shield 35 may be omitted or utilized whenever desired, and the sheet of heat shielding material 26 may be similarly employed or omitted whenever desired or required.

The glass sheet in its flat form is positioned on the mold as shown by the dotted lines-see Fig. 2-and indicated by A when the shield 23 has been removed and this may be readily effected because the glass can be slid upwardly on the portion l5 to seat the opposite end of the glass sheet to the right of the stop [9.

Thereafter the shield 23 is reapplied and then the mold and sheet are subjected to increasing temperatures until glass softening temperature occurs and when that is attained, the sheet sags and conforms to the glass supporting sheet or mold surface. The glass is not softened to the point where it will bulge or bag into the aperture or openwork conformation. The fiat portion of the glass by reason of its upper and lower shielding arrangement, bodily lowers as the glass is softened at the bendable portion until it, in its original planar form, rests upon the flat portion of the glass supporting surface l3 and conforms thereto.

Theshielding prevents the overheating of this glass portion so it will not bag or bulge into the openwork conformation and the peripheral or border support arrangement disclosed is sufficient to support the peripheral border of the glass to .obtain the desired result, hence complete surface support of the glass is notrequired. This means that the surface of the glass not mold contacted is not pitted or burned. In this manner also the glass is shielded both above and below and throughout the area thereof, that is, to be retained flat and hence this flat area of the glass may be said to remain substantially cooler than the exposed portion.

The openwork skeleton like arrangement, it has been found, eliminates to a considerable degree the possibility of pitting and marking of the surface of the glass by reason of particles of dirt being interposed between the glass and the mold. Marginal support of the glass, therefore, has been found not only sufiicient for the fabrication of curved glass having a flat portion but has the additional utility just described.

It, of course, will be understood that different types of bends will require more or. less shielding in order to obtain the necessary temperature differences in the glass sheet and the present method is not confined solely to the treatment of bends where a portion of the sheet remains flat but also applies to the production of a sheet or complementary sheets wherein curvatures of more than one radius, such as an elliptical curve'are included. By shielding selected portions of the glass sheet that are to remain flat, the desired end product can be obtained thus the central area of the sheet could be retained fiat while both end were. being bent or the ends could be retained flat and the central area bent.

The essence of the present apparatus, therefore, is controlling in the manner indicated, the temperature of the various areas of the sheet, or sheets, of glass to be bent, retaining certain portions of said sheet, or sheets, in a rigid state while other areas are heated sufliciently so that they will conform to the shape of the mold.

The shield material utilized and found satisfactory, has been about A" in thickness of as- The term "openwork as used in the descrip tion and claims, is intended to include a single,

opening as well as a plurality of adjacent openings.

While the invention has been illustrated and described in great detail in the drawing and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims. 1

The invention claimed is:

1. A mold structure for bending substantially flat glass sheets to the desired contour-including a base having a plurality of spaced beams rigidly connected together at opposite ends, a

centrally apertured sheet-like template having 1 sheet stop on the template, and heat shielding sheet means beneath the template and registering'with and of greater area than the template aperture and supported by the beams immediately adjacent the template.

2. A structure as defined by claim 1 wherein the beams are inclined and a second sheet heat shielding means is supported by the beams below the first mentioned heat shielding means and offset therefrom, adjacent ends of both heat shielding means overlapping each other, although vertically spaced apart, and imperforate sheetlike support means carried by the beams and constituting the connection therebetween at one end, the sheet-like supportmeans at its upper end supporting the adjacent end of the template.

3. A structure as defined .by claim 1 wherein there is provided upwardly directed supports intermediate the ends of the structure and adjacent the sides thereof and having inwardly directed portions positioned appreciably above the template, and comparatively rigid, sheet-like, heat insulation means resting on said portions and abutting said stop and superposed relative to the template aperture.

4. A structure as defined by claim 1 wherein there is provided a plurality of upwardly directed members rigid with the base and at the end op posite the stop and having portions directed over the template, and sheet-like heat insulating means carried by said portions and positioned above the template.

5. A structure as defined lay claim 1 wherein said heat shielding means is positioned adiacent the stop and extends in a general direction toward the opposite end of the template but terminating appreciably short thereof, said heat shielding means having an area at least as great as that of the template aperture, the beams being inclined, a second heat shielding means positioned below the said opposite end of the template and at a level appreciably below the first mentioned heat shielding means, the heat shielding means being of appreciably less length than base, the major portion of I 4 ammo the end opposite the overisppina end of the secjaeent the adiacent end of the third heatina ond mentioned heat shieldina means for torminz shielding means, appreciably spaced therefrom a circuitous heating channel to the said opposite i'or localizing heat application toward th ternend of thetemplate, a third heat shielding means plate between the said adjacent appreciably supported in spaced relation to and above the a spaced ends oi the said third and fourth mentemplate and extendin: from the stop toward but tioned heat shieldin: means, the lower circuitous terminating appreciably short or the said oppochannel and the upper localized heat applicasite end of the template. and a fourth heat shieldtions being coincident relative to the template. in: means superposed'relative to'the said oppo- EDGAR R. BOYLEB.

site end of the template and havinl its end, ad- 10 CLARENCE M. PA'I'TIBON. 

